When the United Nations outgrew the office accommodation at its 140-acre Gigiri compound in Nairobi, it was clear that any new building had to meet several challenges head-on.

It needed to be energy and water efficient, to reduce and recycle, and to maximize sustainability without compromising the quality of the working environment.

An ambitious goal was set to make the new building energy neutral, where the electricity requirements of the building and its occupants are met over the year by the power generated by solar panels.

In this the designers and project team were helped by the location of the building. There are many who say that Nairobi enjoys an almost perfect climate. Situated almost 1,800 m above sea level and just south of the equator, it benefits from warm, sunny days and cool evenings, and while the two rainy seasons and its ‘winter’ in July and August bring cloud and cooler weather, with good design.

The United Nations compound is a beautiful ‘green lung’ on the outskirts of Kenya’s capital city. More than 600 indigenous tree species are found there, as well as many species of birds and small mammals. Already rainwater is harvested, waste-water recycled, and wetlands maintained. All buildings are cooled by natural ventilation, and office waste is separated and recycled.

But the new building, which staff started to move into last month, takes environmental sustainability to a new level.

Rainwater is collected from the roofs to feed the fountains and ponds at the four entrances, and sewage is treated in a state-of-the-art aeration system and recycled to irrigate the beautifully landscaped compound.

Water saving lavatories, a central atrium and lightwells in every office zone, together with an inventive design that maximizes cooling natural airflow through the building, all contribute further to sustainability.

And far from compromising the working environment, the new building and its environmentally responsible features are acknowledged to be a huge enhancement of the surroundings and comfort in which its new occupants work.

There were those who doubted it would be possible to bring in such an ambitious project on time and in budget, and they have been proved decisively wrong.

Instead the new office facility has become an international showcase for sustainable buildings, and a central pillar of the United Nations broader goal of reducing its greenhouse gas emissions.

Achim Steiner, Director-General of the United Nations Office at Nairobi, sees the new office facility in Nairobi as the perfect opportunity for UNEP and UN-HABITAT to walk the talk on sustainable buildings and climate change:

“This is a working building but it is also in many ways a research facility and a sustainable building showcase. We invite other United Nations duty stations, and architects and planners from Kenya, across the continent and beyond, to come, learn and become part of a community that is helping sustainable buildings to play their role in a greener future.”